Method and apparatus for inside coating bulbs



Aug. 4, 1931. K. TSUYUKI IMETHOD AND APPARATUS FOR LNSIDE COATING BULBSFiled Sept. 30, 1927 I'nve-ntor": I Kei ji Tsuguki,

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Application inea September so, 1927, Serial n. 223,147, and in as... 0mmso, 1920.

The present invention relates to a method facturing lamps which are halffrosted or a of and ap aratus for applying to apart of the bowl frostedonthe outside b an etchin inner sur ace'of a lamp bulb or similar glasscompound isimpossible; to picli up the bulb containerhaving only oneneck or opening carefully and inside frost the bowl of the bulb 5 aprotective coating prior to frosting theunby gfntly pouring the etchingcompound into 55 coated part of the inner surface by etchin the ulbwhile held bowl down is troublesome and more particularl to coating aselects and requires skill; and sand blasting the ingfi'll' of the innersur ace of the bulb with a side of the bowl of the bulb is attended byof protective material, preferablyby many difliculties and troubles ifdone on a dipping it neck downward into said material commercial scale.By the presentinvention, c in liquid form, and venting the air in thehowever, the bowl art of the inside of the bulb to the atmosphere so asto cover the bulb can be frosted y'practically any frostsubmergedportion of the bulb with a film lng process, because a protective filmnot afwhich tprotects the glass surface from. the fected by the etchingor frosting compound is,

etching compound. by a simple and easy operation which requires as Theobject of the invention is to provide no skill, ap lied to the partwhich is not to be simple and reliable means for coating a bulb frosted.T e invention can be practiced by or similar article on only a part ofthe. inside hand, but I prefer to coat that portion of the surface, andto accurately limit in a simple inside of the bulb which is to'remainclear way not requirin an particular skill the with a film of aprotective material resistant m area afiected by the etc g compound. tothe etching compound by means of a malhe invention relates moreparticularly to chine which handles the bulbs to form a'film amethod ofconfinin the frosting to a preof a protective material, such asparafiin, on determined art of t e inside surface of a a desired portionof the inside of the bulb, bulb or sim'v a1 empty glass container havandfixes the film on the glass by cooling it. 16 ing one neck or opening,by placing the bulb lhen the uncoated portion of the inside of with theopening downward, venting the inthe bulb is frosted, usually by amachine. terior of the bulb by connecting it to the at- The inventionwill best be understood in mosphere, as for example,by means of aconconnection with the accompanyin drawings, necting (tube, and dippingthe bulb into the in which one embodiment of the invention is so liquidprotective material to such a depth illustrated and in which Fi e l is aview that the only part which remains free from in perspective withparts bro en away of one a film or coating of the protective material isform of apparatus for applying the protecthat p artof the inside surfacewhich is to tive film priorto frosting, and Figure2 shows be frosted ythe etchin compound, which the coated bulb produced on the-machine, s5-

usually contains hydrouoric acid. A sat- The particular machine showncomprises isfactory material for protecting the glass a table 1 on whichseveral heads construe d from the etching c0mpound,'and one that to holdthe bulbs aremounted to recipr has a low melting point and easily coatsthe vertically and also travel step by-step along glass surface, isparafiin or wax. a circular path. -Each head or bulb holder 90 It hasheretofore been considered diflicult comprises bulb clamps 5 and 6secured to the to frost only a part of the inside surface of lower part'of'a vertical rod 4 suspended from a bulb having only one neck oropening and an arm of a spider fixed to the upper part w articularly tomanufacture by the inside of a reciprocating and rotatablerarrier forrost method the so-called half frosted or the heads, such as a shaft 2WhlCh extends 9 bowl frosted lamp and keep the half near the verticallythrough the table 1. Each head neck transparent and frost the other halfholds the bulb with its neck downward and toward the bowl or top,although there is 8. its longitudinal ans vertica To the lower lar 'edemand for such lamps. To use the part of the carneror shaft 29. drwmgmechordmary method and apparatus for manuanisrn is attached in order toreciprocate and 1 0 highest position, where it is rotated one step tomove the head or bulb support from one working position to the next, andsince, in the apparatus shown in the drawings, there 5 are four headsthe shaft makes one revolution in four steps, so that the shaft 2 turnsone fourth of a revolution each time it rotates. The driving mechanismfor rotating the shaft intermittently is preferably a Geneva gearcomprising a notched wheel 9 with a film that protects the glass surfaced splined on the shaft 2 to rotate it regardless of the reciprocatingmovement of the said shaft and making one fourth of a revolutlon foreach revolution of the driving pinion 10- which has a pin 11 to engagethe notches on the wheel 9. The relative speeds of the countershaft 12for the cam 8 and the driving shaft 13 of the pinion 10' are such thatwhen the shaft 2 is in its highest position the Geneva gear rotates itone fourth of a revolution. Each head or bulb support is lifted by thecam 8 at each working position and while lifted it is rotated one fourthof a revolution by the Geneva gear to the next working position where itis lowered and this operation is repeated to carry each head from oneworking position to another.

The coatmg device by which any desired part of the bu b supported in ahead is coated from. the effect of the etching compound, is placed atone of the points where the head or bulb supports stop as the shaft 2intermittently rotates on the table 1. The particular device showncomprises a tank 14 for a static or quiet body or pool of paraflin orwax,

' which is resistant to an etching compound containing hydro-fluoricacid, and in the tank is a heating coil, suchas a steam pipe. 15 whichextends outside the tank. The is melted and rendered liquid by heatingit. To rmit the li uid paraflin to rise inside the b ulb to the evel ofthe uiet body of melted paraflin in the tankthe ulb is vented throughthe neck by some means, such as a vent pipe 16 which stands verticallyin the tank and opens through the bottom of the tank and is somounted-that it is inali ent with the axis of the bulb held by the bulbinto the static body of melted paraflin as the bulb is lowered with the,bulb su port, the vent ipe assists the bulb to sink into the para byexhausting or venting the air in the bulb to the outside.

7 ens the paraflin film on paraflin be fr 0 support, so that as the neckof thebulb sinks A filmfixing device, which sets and hard the glasssurface may be placed on the table 1 in one of the working positionsreached by the head 'durin travel. The ap aratus shown in the ingsfacilitates h rawardening of the coating by itsso locating the fixingdevice that each head stops between the coating device and the fixingdevice (position 0) to permit the excess parafiin to drain oil and thecoating to cool to some extent. However, it is not always necessary todo so. The film .fixing device comprises an open ended vessel or tank 18havin an outlet pipe 17 at the bottom, and a for ed inlet pi 19 with apluralit of orifices or sprink ers so placed that a ulb,

lowered into the tank by the head in which it'is supported, issurrounded by said water pipe 19 whereby the araflin coat on the glassis sufliciently cooled y water sprinkled on it, thereby fixing thecoating.

The next stop of the head is at .the loading and delivery position Awhere the operator who stands at this position A removes the coated.bulb and inserts an uncoated transparent bulb into the bulbclamps 5 and6 while the head is stationar The shaft 2 lifts the bulb and the headbecause of the rotation of the shafts 12 and 13, transfers it to thecoating position B, and then lowers it into the quiet pool of meltedparaflin in the tank 14. The extent of dipping the bulb into the araflinis varied as desired by adjusting t e point of attachment of the rod 4to the arm 3 in accordance with the height of surface of the paraflinand the extent of the portion of the bulb to be coated with protectivefilm. The bulb is lowered and is pool of parafiin as dipped into'theguiet eep as the boun a l ne of the area desired to be coated. T en,since the air sealed in the bulbas the neck enters theparaflin canescagelfreely throu h the vent pipe 16 the para surface inside the bulbequalizes with that on the outside so that the inside surface of thebulb except the part where frosting is desired is completely wetby theparaflin and-when lifted up by the-head all inner surface of the bulb,except the part to osted, is coated with paraflin. According to the kindof paraflin, and the temperature of the location of the apparatus thebeen coated with paraflin at B is transferred step by step to theposition D and there goes down into the fixing tank 18 with the resultthat the Paraflin is cooled and sticks to the glass sur ace because ofthe shower of water sprinkled upon it from pipe 19.

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When the bulb comes back to position A the operator takes the bulb whichis coated with parafin out of the support and replaces it with anuncoated bulb. I

The bulb that has been coated with the protective film of araflin on apart of the inside surface may frostedby any known method and apparatus,and then the protective film or coat on the glass surface is taken ofipreferably by blowing into the bulb an alkaline steam.

What is shown in the drawings is an apparatus for facilitating thecarrying out of the preparation of the bulb, but if the position forblowing'the alkaline steam into the frosted bulbs be placed in properrelation to the working positions of the inside frosting machine forincandescent electric lamps orsimilar articles the troubles duetotransfer of the coated and frosted bulbs to different machines aregreatly lessened.

The bulb 20 after it has been coated by the machine as above describedhas, as best shown in Figure 2, a thin protective coating of parafin 21on the inside which leaves only the bowl of the bulb exposed to theetching compound.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, is

1. The method of temporarily coating a portion of the inside surface ofa hollow glass article having one opening which consists in submergingthe opening of the article to a pre-determined depth in a static 'poolof molten liquid coating material, venting the article through saidopening to permit the molten material to rlsein said article and therebywet a pre-determined portion of its inner surface, cooling said articleto convert the adherent material on the wetted surface into a solidprotective coating and subsequently removing said coating.

2. The method of temporari y coating :1. portion of the inside surfaceof a hollow glass article having one opening which consists insubmerging the o ning ofthe article to a predetermined dept in liquidparaflin,

venting the article through said opening to protecto reciprocatevertically, an open ended 'coating vessel mounted on said table with itsopen end adjacent the path of said holder, a vertical vent pipe insidesaid vessel in alignment with the axis along which said bulb holderreciprocates, an open ended fixing vessel on said table with its openend adjacent the path of said holder,-and actuating means forintermittently rotating said holder to bring it into registry with saidvessels in succession, and to lower said holder while in registry withsaid coating vessel to dip the neck of a bulbinto said vessel and oversaid vent pipe and then raise said holder, and to lower the bulb intoand raise it out of said fixing vessel while said holder is in: registrywith said fixing vessel.

. In witness whereof, I have hereunto set my hand this 6th day ofSeptember, 1927.

' KEIJI TSUYUKI.

permit the parafiin to rise inside said article to the same level asoutside, and thereby wet a predetermined portion of said inner surface,cooling the coated article to convert the adherent liquid paraflin onthe wetted surface into a solid protective coating, and subsequentlyremoving said solid coating by treatment with an alkaline reagent.

3.- The method of temporarily coating 2. portion of the inside surfaceof a hollow glass article having one opening which consists in submer'ng the opening of the article to a predetermined depth in a bath ofheated pra, venting the article through said opening to permit heatedparatfin to rise in said article to the outside level of the bath andthereby wet a predetermined por-

